CREECH, J.E.; Florida State University: Variation in Crocodylian Enamel Microstructure

Tooth enamel microstructure has been shown to be variable among mammals. Such variation has a major bearing upon whole tooth biomechanical function and may reflect gross-level phylogenetic signal. Although variation is substantial within reptilian lineages, comprehensive standardized sampling has not been done from which a similar understanding can be garnered. In the present study I sampled caniniform teeth from all 23 extant species of crocodylians. The 3-dimensional enamel microstructure was characterized by examining the tooth enamel in longitudinal, transverse, and oblique-tangential views using scaning electron microscopy. Biomechanical testing is being conducted using nanoindentation. The results show that the amount of longitudinal wrinkling varies between species, and contributes greatly to the tooth surface morphology and may contribute to variable fracture toughness.